H/E Lecture 6

Question 0

What signaling molecules are associated with neural crest differentiation?

Answer 0

Snail determines neural crest cell fate

Slug promotes cell migration

Question 1

What establishes left right asymmetry?

Answer 1

At beginning of week 3, FGF-8 affects cilia development to sweep left. Nodal from the primary node is swept left. Nodal induces lateral plate mesoderm to form left structures by promoting Pitx2.

Question 3

What time frame is the CNS beginning to be formed?

Answer 3

Week 3 during Neurulation

Question 4

During neurulation, BMP4 from ectoderm induces expression of what genes in the ectoderm?

Answer 4

Pax 3 and Pax 7

Question 5

What signaling molecule is responsible for mesoderm specification?

Answer 5

BMP4 coming from the lateral edges of the mesoderm.

Question 6

What does Retinoic acid do?

Answer 6

It is a signaling protein that causes expression of Hox genes which promote somite development.

Question 7

What dies FGF-8 do to somites?

Answer 7

It is a signaling protein that inhibits Hox expression and therefore inhibits somite development.

Question 8

What signaling protein induces sclerotome?

Answer 8

SHH from the notochord causes the paraxial mesoderm to become sclerotome.

Question 9

What signaling protein induces myotome?

Answer 9

Wnt from the neural tube and the surface ectoderm causes myotome formation.

Question 10

What signaling protein induces dermatome?

Answer 10

NT-3 from the top of the neural tube causes dermatome formation.

Question 11

Which transcription factors are affected by RA, SHH, WNT, NT-3?

Answer 11

RA-> Hox->Somite
SHH->Pax1->Sclerotome
WNT->Myod, Myf5->myotome
NT-3->Pax3->Dermatome